Madeleine Potter and Donald Sage Mackay complete the cast of the show, which opens in previews on 23 November.

Potter will play Mom, while Mackay is to take the role of Hollywood producer Saul Kimmer. The already announced Harington and Flynn play brothers Austin and Lee.

Potter's credits include An Ideal Husband (West End and Broadway), The Crucible (Broadway), All My Sons (National Theatre) and Pygmalion (Roundabout Theatre). Mackay recently starred in Angry Alan in Edinburgh and has performed in A Moon for the Misbegotten (Lyric).

Sam Shepard's play is set in the California desert where brothers go head to head as a family tears itself apart.

Matthew Dunster directs the piece, with set and design from Jon Bausor, lighting design from Joshua Carr and sound design from Ian Dickinson. Flynn has written the original music for the production.